1. Field of the Invention
This invention relates to electroplating devices and more particularly to an electroplating bath for plating materials moving in a constant transit through the bath, the bath having an internal fluid flow control vanes.
2. Prior Art
This invention relates to electroplating devices for the partial metalization of items in continuous movement. Such devices having at least one treatment bath which is arranged along the path followed by the items and in which the end walls of the bath are equipped with slots through which the items move with the treatment liquid flowing out of the bath through the slots and being recirculated back to the bath from the delivery side of a circulation pump, are known to the art.
Such continuously operating electroplating devices are shown for example in German Offenlegungsschrift No. 1,796,017. In such devices, the items, for example relay springs and the like, which are to be partially electroplated, are conveyed on a transfer device through a plurality of elongated treatment baths. Only those zones or areas of the items which are to be metalized are actually dipped into the corresponding liquids. In order that the items, in transit, can be passed through the treatment liquids at a constant level, i.e. at a constant penetration depth, the end faces of the treatment baths are provided with slots. The liquid levels in the treatment baths are maintained constant by means of circulation pumps which continuously pump treatment liquids flowing out through the slots back into the corresponding treatment baths. Because of the constant level of treatment liquid within the bath, and because of the constant movement of the itmes are a predetermined penetration depth through that liquid, such prior devices have made possible partial electroplating with the deposition of metal restricted to specific zones or areas. This allows reduction of metal consumption which in turn leads to considerable cost savings, particularly where gold and other valuable metals are involved.
One disadvantage with the prior art, however, arises in that the items treated in such devices may exhibit differing thicknesses of the electro deposited metal layer. The differences in layer thicknesses distribution have often been on the order of 100%. Since, for reliable operation of the electroplated items in use after plating specific deposited layer thickness minimums must be maintained, it would be possible to obtain a further, and substantial, reduction in metal consumption by obtaining a more uniform layer thickness distribution.